This invention relates to the display of subtitles during play of a software (e.g., motion picture) carrier, and more particularly to a technique by which subtitles in multiple languages are recorded on the same carrier with provision for selecting one language for display.
Before summarizing the invention, it is to be appreciated that the present invention contemplates data-efficient storage and recovery of various audio and subtitle presentations, and not just different language movie soundtracks and subtitles. For example, multiple soundtracks and subtitle captions could include teaching and testing versions of the same material, and there could perhaps be teaching and testing versions for multiple levels of expertise. Thus, it is to be understood that the object of the invention is to provide a plurality of subtitle sequences synchronized with a motion picture (video and audio), and not necessarily such sequences which differ only in terms of language. It is also to be understood that the invention is not limited to a particular medium, and it is applicable to tape carriers and all digital storage media, not just the optical disks of the illustrative embodiment of the invention. Nor is the invention limited only to the distribution of motion pictures. For example, in an extreme case, the invention is applicable to the distribution of a library of still pictures, in which case there is no xe2x80x9cmotionxe2x80x9d at all. The terms xe2x80x9csubtitle tracksxe2x80x9d and xe2x80x9csubtitle sequencesxe2x80x9d thus embrace much more than movie subtitles in different languages, the term xe2x80x9csoftware publisherxe2x80x9d thus embraces much more than a motion picture company, and the term xe2x80x9ccarrierxe2x80x9d embraces much more than a digitally encoded optical disk. As used herein, the term xe2x80x9csubtitlexe2x80x9d refers to any text, displayed anywhere on an image.
The illustrative embodiment of the invention is an optical disk which includes multiple audio tracks and multiple subtitle tracks synchronized with a motion picture track. The user selects one of the audio tracks, the French track, for example, if he wants to hear the French version of the movie. If there is no audio track in his/her language, this selection is not particularly important. What is more significant in such a case is the selection of the subtitle language.
The disk includes within its lead-in section a series of codes which identify the available subtitle languages. There are a maximum of 99 subtitle tracks which may be provided. It is necessary to identify which languages are available on the disk so that the user can control his player to generate subtitles in the desired language, by reading subtitle sequences in a selected track.
Information recorded on the software carrier is recorded in separately identifiable blocks. This is true for both video, all of the synchronized audio, and all subtitles. Each block contains indicia of which subtitle tracks in the block contain update information. In general, once a subtitle caption is generated, it remains in view. It is removed, with or without a new subtitle taking its place, only when new subtitle data is read from the carrier. All it takes is a single bit for each of the subtitle tracks at the beginning of a block to allow the player to determine whether respective language-specific subtitle information is in the block being processed.
Other features of the invention will be described below. For example, a citizen of Spain, who purchases a player and optical disks in Spain, can be assumed to want to see Spanish subtitles of a xe2x80x9cforeignxe2x80x9d motion picture. Therefore, a player sold in Spain should xe2x80x9cdefaultxe2x80x9d to play of a Spanish subtitle track if one is available on the disk (assuming that subtitles are desired at all). Only if the default language is not available, or the user actually wants to see subtitles in a different language, should she be required to choose from among the available languages. How the data is stored on software carriers, and how it is accessed and played, will be discussed at length below.
The invention is disclosed in the context of an overall system which offers numerous advantageous features. The entire system is described although the appended claims are directed to specific features. The overall list of features which are of particular interest in the description below include:
Video standard and territorial lock out.
Play in multiple aspect ratios.
Play of multiple versions, e.g., PG-rated and R-rated, of the same motion picture from the same disk, with selective automatic parental disablement of R-rated play.
Encrypted authorization codes that prevent unauthorized publishers from producing playable disks.
Provision of multiple-language audio tracks and multiple-language subtitle tracks on a single disk, with the user specifying the language of choice.
Provision of multiple xe2x80x9cotherxe2x80x9d audio tracks, e.g., each containing some component of orchestral music, with the user choosing the desired mix.
Variable rate encoding of data blocks, and efficient use of bit capacity with track switching and/or mixing, to allow all of the above capabilities on a single carrier.